SqlCeDataReader Class

Provides a way of reading a forward-only stream of data rows from a data source. This class cannot be inherited.

Inheritance Hierarchy

System.Object
  System.MarshalByRefObject
    System.Data.Common.DbDataReader
      System.Data.SqlServerCe.SqlCeDataReader
        System.Data.SqlServerCe.SqlCeResultSet

Namespace:  System.Data.SqlServerCe
Assembly:  System.Data.SqlServerCe (in System.Data.SqlServerCe.dll)

Syntax

'Declaration
Public Class SqlCeDataReader _
    Inherits DbDataReader
'Usage
Dim instance As SqlCeDataReader

public class SqlCeDataReader : DbDataReader

public ref class SqlCeDataReader : public DbDataReader

type SqlCeDataReader =  
    class
        inherit DbDataReader
    end

public class SqlCeDataReader extends DbDataReader

The SqlCeDataReader type exposes the following members.

Properties

	Name	Description
	Depth	Gets a value indicating the depth of nesting for the current row. (Overrides DbDataReader.Depth.)
	FieldCount	Gets the number of columns in the query's SELECT clause. (Overrides DbDataReader.FieldCount.)
	HasRows	Gets a value that indicates whether the SqlCeDataReader contains one or more rows (Overrides DbDataReader.HasRows.)
	HiddenFieldCount	Infrastructure.
	IsClosed	Indicates whether the data reader is closed. (Overrides DbDataReader.IsClosed.)
	Item[Int32]	Gets the value of the specified column in its native format given the column ordinal. (Overrides DbDataReader.Item[Int32].)
	Item[String]	Gets the value of the specified column in its native format given the column name. (Overrides DbDataReader.Item[String].)
	RecordsAffected	Gets the number of rows changed, inserted, or deleted by execution of the SQL statement. (Overrides DbDataReader.RecordsAffected.)
	VisibleFieldCount	(inherited from DbDataReader)

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Methods

	Name	Description
	Close	Closes the SqlCeDataReader object. (Overrides DbDataReader.Close().)
	CreateObjRef	(inherited from MarshalByRefObject)
	Dispose()	Infrastructure. Releases the resources consumed by this SqlCeDataReader.
	Dispose(Boolean)	Releases the unmanaged resources used by this SqlCeDataReader, and optionally releases the managed resources as well. (Overrides DbDataReader.Dispose(Boolean).)
	Equals	(inherited from Object)
	Finalize	Releases unmanaged resources and performs other cleanup operations before the SqlCeDataReader is reclaimed by garbage collection. (Overrides Object.Finalize().)
	GetBoolean	Gets the value of the specified column as a Boolean. (Overrides DbDataReader.GetBoolean(Int32).)
	GetByte	Gets the value of the specified column as a byte. (Overrides DbDataReader.GetByte(Int32).)
	GetBytes	Reads a stream of bytes from the specified column offset into the buffer as an array starting at the given buffer offset. (Overrides DbDataReader.GetBytes(Int32, Int64, array<Byte[], Int32, Int32).)
	GetChar	Not supported in the .NET Compact Framework Data Provider for SQL Server Compact. (Overrides DbDataReader.GetChar(Int32).)
	GetChars	Reads a stream of characters from the specified column offset into the buffer as an array starting at the given buffer offset. (Overrides DbDataReader.GetChars(Int32, Int64, array<Char[], Int32, Int32).)
	GetData	(inherited from DbDataReader)
	GetDataTypeName	Gets the name of the source data type. (Overrides DbDataReader.GetDataTypeName(Int32).)
	GetDateTime	Gets the value of the specified column as a DateTime object. (Overrides DbDataReader.GetDateTime(Int32).)
	GetDbDataReader	(inherited from DbDataReader)
	GetDecimal	Gets the value of the specified column as a Decimal object. (Overrides DbDataReader.GetDecimal(Int32).)
	GetDouble	Gets the value of the specified column as a double-precision floating point number. (Overrides DbDataReader.GetDouble(Int32).)
	GetEnumerator	Infrastructure. (Overrides DbDataReader.GetEnumerator().)
	GetFieldType	Gets the Type that is the data type of the object. (Overrides DbDataReader.GetFieldType(Int32).)
	GetFloat	Gets the value of the specified column as a single-precision floating point number. (Overrides DbDataReader.GetFloat(Int32).)
	GetGuid	Gets the value of the specified column as a globally unique identifier (GUID). (Overrides DbDataReader.GetGuid(Int32).)
	GetHashCode	(inherited from Object)
	GetInt16	Gets the value of the specified column as a 16-bit signed integer. (Overrides DbDataReader.GetInt16(Int32).)
	GetInt32	Gets the value of the specified column as a 32-bit signed integer. (Overrides DbDataReader.GetInt32(Int32).)
	GetInt64	Gets the value of the specified column as a 64-bit signed integer. (Overrides DbDataReader.GetInt64(Int32).)
	GetLifetimeService	(inherited from MarshalByRefObject)
	GetName	Gets the name of the specified column. (Overrides DbDataReader.GetName(Int32).)
	GetOrdinal	Gets the column ordinal, given the name of the column. (Overrides DbDataReader.GetOrdinal(String).)
	GetProviderSpecificFieldType	Gets a Object that is a representation of the underlying provider-specific field type. (Overrides DbDataReader.GetProviderSpecificFieldType(Int32).)
	GetProviderSpecificValue	(inherited from DbDataReader)
	GetProviderSpecificValues	(inherited from DbDataReader)
	GetSchemaTable	Returns a DataTable that describes the column metadata of the SqlCeDataReader. (Overrides DbDataReader.GetSchemaTable().)
	GetSqlBinary	Gets the value of the specified column as a SqlBinary.
	GetSqlBoolean	Gets the value of the specified column as a SqlBoolean.
	GetSqlByte	Gets the value of the specified column as a SqlByte.
	GetSqlDateTime	Gets the value of the specified column as a SqlDateTime.
	GetSqlDecimal	Gets the value of the specified column as a SqlDecimal.
	GetSqlDouble	Gets the value of the specified column as a SqlDouble.
	GetSqlGuid	Gets the value of the specified column as a SqlGuid.
	GetSqlInt16	Gets the value of the specified column as a SqlInt16.
	GetSqlInt32	Gets the value of the specified column as a SqlInt32.
	GetSqlInt64	Gets the value of the specified column as a SqlInt64.
	GetSqlMoney	Gets the value of the specified column as a SqlMoney.
	GetSqlSingle	Gets the value of the specified column as a SqlSingle.
	GetSqlString	Gets the value of the specified column as a SqlString.
	GetString	Gets the value of the specified column as a string. (Overrides DbDataReader.GetString(Int32).)
	GetType	(inherited from Object)
	GetValue	Gets the value of the column at the specified ordinal in its native format. (Overrides DbDataReader.GetValue(Int32).)
	GetValues	Gets all the attribute columns in the current row. (Overrides DbDataReader.GetValues(array<Object[]).)
	InitializeLifetimeService	(inherited from MarshalByRefObject)
	IsCommandBehavior	Determines whether the specified CommandBehavior matches that of this SqlCeDataReader.
	IsDBNull	Gets a value indicating whether the column contains nonexistent or missing values. (Overrides DbDataReader.IsDBNull(Int32).)
	MemberwiseClone()	(inherited from Object)
	MemberwiseClone(Boolean)	(inherited from MarshalByRefObject)
	NextResult	Not supported in the .NET Compact Framework Data Provider for SQL Server Compact. (Overrides DbDataReader.NextResult().)
	OnMove	Infrastructure.
	Read	Advances SqlCeDataReader to the next record. (Overrides DbDataReader.Read().)
	Seek	Places the SqlCeDataReader on the record with indexed values that match the specified parameters.
	ToString	(inherited from Object)

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Explicit Interface Implementations

	Name	Description
	IDataRecord.GetData	(inherited from DbDataReader)

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Remarks

To create a SqlCeDataReader, you must call the ExecuteReader method of the SqlCeCommand object, rather than directly using a constructor.

While the SqlCeDataReader is in use, the associated SqlCeConnection is busy serving the SqlCeDataReader. In this state, you can create multiple readers in the same connection.

Changes made to a result set by another process or thread while the data is being read may be visible to the user of the SqlCeDataReader; however, the precise behavior is dependent on when these occur.

IsClosed and RecordsAffected are the only properties you can call after the SqlCeDataReader is closed. Although the RecordsAffected property can be accessed at any time while the SqlCeDataReader exists, always call Close before returning the value of RecordsAffected to ensure an accurate return value.

Examples

The following example creates a SqlCeConnection, a SqlCeCommand, and a SqlCeDataReader. The example reads through the data and writes it out to the console, and then closes the SqlCeDataReader and the SqlCeConnection.

Dim conn As SqlCeConnection = Nothing
Dim cmd As SqlCeCommand = Nothing
Dim rdr As SqlCeDataReader = Nothing

Try
    ' Open the connection and create a SQL command
    '
    conn = New SqlCeConnection("Data Source = AdventureWorks.sdf")
    conn.Open()

    cmd = New SqlCeCommand("SELECT * FROM DimEmployee", conn)

    rdr = cmd.ExecuteReader()

    ' Iterate through the results
    '
    While rdr.Read()
        Dim employeeID As Integer = rdr.GetInt32(0) ' or: rdr["EmployeeKey"];
        Dim lastName As String = rdr.GetString(5) ' or: rdr["FirstName"];
    End While

    ' Always dispose data readers and commands as soon as practicable
    '
    rdr.Close()
    cmd.Dispose()
Finally
    ' Close the connection when no longer needed
    '
    conn.Close()
End Try

SqlCeConnection conn = null;
SqlCeCommand cmd = null;
SqlCeDataReader rdr = null;

try
{
    // Open the connection and create a SQL command
    //
    conn = new SqlCeConnection("Data Source = AdventureWorks.sdf");
    conn.Open();

    cmd = new SqlCeCommand("SELECT * FROM DimEmployee", conn);

    rdr = cmd.ExecuteReader();

    // Iterate through the results
    //
    while (rdr.Read())
    {
        int employeeID = rdr.GetInt32(0);   // or: rdr["EmployeeKey"];
        string lastName = rdr.GetString(5); // or: rdr["FirstName"];
    }

    // Always dispose data readers and commands as soon as practicable
    //
    rdr.Close();
    cmd.Dispose();
}
finally
{
    // Close the connection when no longer needed
    //
    conn.Close();
}

Thread Safety

Any public static (Shared in Microsoft Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also

Reference

System.Data.SqlServerCe Namespace